From 75dbf79c9c324947f479a2c785d2e629644d0f15 Mon Sep 17 00:00:00 2001
From: Adrian Cochrane <adrian@openwork.nz>
Date: Tue, 29 Nov 2022 14:53:54 +1300
Subject: [PATCH] Bind CSS 'font-variation-settings' to FontConfig 'variable'
 property.

---
 Graphics/Text/Font/Choose/Pattern.hs | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/Graphics/Text/Font/Choose/Pattern.hs b/Graphics/Text/Font/Choose/Pattern.hs
index c26de01..3d17b35 100644
--- a/Graphics/Text/Font/Choose/Pattern.hs
+++ b/Graphics/Text/Font/Choose/Pattern.hs
@@ -190,6 +190,13 @@ parseFontFeatures (String feat:toks) | feature@(_:_:_:_:[]) <- unpack feat = cas
     Number _ (NVInteger x):tail -> ([(feature, fromEnum x)], True, tail)
 parseFontFeatures toks = ([], False, toks)
 
+parseFontVars :: [Token] -> ([(String, NumericValue)], Bool, [Token])
+parseFontVars (String var':Number _ x:Comma:tail) | var@(_:_:_:_:[]) <- unpack var' =
+    let (vars, b, tail') = parseFontVars tail in ((var, x):vars, b, tail')
+parseFontVars (String var':Number _ x:tail) | var@(_:_:_:_:[]) <- unpack var' =
+    ([(var, x)], True, tail)
+parseFontVars toks = ([], False, toks)
+
 parseLength :: Double -> NumericValue -> Text -> Double
 parseLength super length unit = convert (nv2double length) unit
   where
@@ -211,6 +218,7 @@ parseLength super length unit = convert (nv2double length) unit
 sets a b c d = Just $ setValues a b c d
 set a b c d = Just $ setValue a b c d
 seti a b c d = Just $ setValue a b (c :: Int) d
+unset' a b = Just $ unset a b
 
 getSize pat | ValueDouble x <- getValue "size" pat = x
     | otherwise = 10
@@ -262,9 +270,15 @@ instance PropertyParser Pattern where
         | ValueInt _ <- getValue "weight" self = Just self -- As bold as it goes...
         | otherwise = seti "weight" Strong 200 self
 
-    longhand _ self "font-feature-settings" [Ident k] | k `elem` ["initial", "normal"] = Just self
+    longhand _ self "font-feature-settings" [Ident k]
+        | k `elem` ["initial", "normal"] = unset' "fontfeatures" self
     longhand _ self "font-feature-settings" toks
         | (features, True, []) <- parseFontFeatures toks =
             set "fontfeatures" Strong (intercalate "," $ map fst features) self
 
+    longhand _ self "font-variation-settings" [Ident k]
+        | k `elem` ["initial", "normal"] = unset' "variable" self
+    longhand _ self "font-variation-settings" toks
+        | (_, True, []) <- parseFontVars toks = set "variable" Strong True self
+
     longhand _ _ _ _ = Nothing
-- 
2.30.2